24084B bearing: complete specifications & equivalents
The 24084B is a ISO 15 radial bearing sized 420 x 620 x 200 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 420 mm |
| Outer diameter D | 620 mm |
| Width B | 200 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 4300 kN |
| Basic static load rating C0 | 8450 kN |
| Fatigue load limit Pu | 470 kN |
| Limiting speed (mechanical) | 440 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 210000 g |
| Manufacturer designation | NTN 24084B |
| Standard | ISO 15 |
| Catalog version | NTN Ball and Roller Bearings CAT.No.2203E |
| Last verified | 2026-10-01 |
Source: catalog reference (NTN Ball and Roller Bearings CAT.No.2203E) · extracted 2026-10-01
Parameters extracted from the official NTN Ball and Roller Bearings catalogue (NTN Ball and Roller Bearings CAT.No.2203E); NTN® is a trademark of NTN Corporation, used here for identification only — mpnbase is not an authorized NTN distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at ntnglobal.com.
Dimensions in inches & 24000-series range
| Bore d | 16.535 in |
|---|---|
| Outer diameter D | 24.409 in |
| Width B | 7.874 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 100 mm |
| Smallest bore in 24000-series | 65 mm |
| Largest outer diameter in 24000-series | 1580 mm |
| Width range across 24000-series | 35–462 mm |
| Bore position in 24000-series (smallest first) | 24 of 42 |
| Bore above smallest 24000-series size | 355 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 24084BK30 | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same NTN 24000-series envelope, cage and ratings; this is the cylindrical-bore execution of the tapered-bore 24084BK30 (K/K30 sleeve or tapered-seat mounting). Verify shaft arrangement. |
Interchange levels: full standard interchange · partial verify parameters · verify manual confirmation required. Links resolve to the equivalent model's specification page where available.
How the 24084B model number is decoded
The NTN order number 24084B identifies a 420×620×200 mm (16.535 × 24.409 × 7.874 in) spherical roller bearing, cylindrical bore, to the ISO 15 boundary plan. Digit by digit the code reads as spherical-roller dimension series plus 420 mm bore; the 200 mm width is the wide ISO 15 section, which is why spherical rollers interchange dimensionally but not in cage or rating detail. Two symmetric roller rows share the load: C 4300 kN, C0 8450 kN (C0/C ≈ 1.97), with useful axial capacity in either direction alongside the dominant radial load. 420 mm bore is 16.535 in and 620 mm OD is 24.409 in; the ISO 15 envelope swaps between brands, but the 4300/8450 kN ratings and cage design are NTN 2203E values. Never mount 24084B by striking the outer ring through the roller set; drive through ring faces (or the adapter sleeve nut) and support the ring square to avoid brinelling the 620 mm race.
Typical equipment & failure modes
Common applications
- large SAG/ball-mill trunnion and pinion shafts
- heavy vibrating screens and grizzly feeders
- offshore and marine propulsion shaftlines
- large wind-turbine main-shaft arrangements
Known failure patterns
- raceway spalling at the roller ends when misalignment or deflection concentrates the line contact
- machined EM cage wear from inadequate oil film at the cage-guiding surfaces
- roller-end smearing during skidding starts under light load and high viscosity grease
- hard-particle indentation through the open arrangement in dusty mining duty
- water-induced pitting in washdown or outdoor duty without effective external seals
Selection pitfalls — read before you substitute
- At 420 mm bore 24084B is normally mounted on adapter/withdrawal sleeves with hydraulic assistance; follow the NTN drive-up angle or oil-injection procedure — manual nut tightening cannot set the multi-tonne seating correctly.
- Self-aligning does not mean unlimited misalignment: beyond the catalogue angle the outer ring's spherical travel is exhausted and the 4300 kN rating no longer applies.
- Never substitute 24084B by envelope alone: the 8450 kN C0 and 470 kN Pu are specific to the NTN basic execution, and vibrating duty depends heavily on cage identity.
- Open spherical rollers swallow dust in mining duty; specify labyrinth or taconite seals externally, or the 440 r/min grease rating is lost to abrasive wear long before fatigue.
- Adapter-sleeve mounting requires the correct sleeve series and locknut for the 420 mm shaft; a sleeve sized to bore alone ignores thread, width and the oil-injection option on large K30 seats.
- The 4300/8450 kN ratings, 470 kN Pu and 210000 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 24084B (basic); another maker's same-envelope part revises internal geometry, so re-verify ratings and cage before substitution on vibrating or rated drives.
Frequently asked questions
What are the dimensions and catalogue data of 24084B?
24084B is an NTN double-row spherical roller bearing to ISO 15: 420 mm bore, 620 mm OD and 200 mm width (16.535 × 24.409 × 7.874 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 4300 kN, C0 8450 kN, Pu 470 kN, grease limiting speed 440 r/min, oil 570 r/min, mass about 210000 g. It is open, with pressed-steel cage (standard execution).
What is the difference between the K/K30 tapered bore and the cylindrical bore versions?
24084B has a cylindrical bore and mounts directly on a machined shaft seat. Its tapered-bore counterpart is 24084BK30 (K = 1:12, or K30 = 1:30 on the wide series), intended for adapter/withdrawal-sleeve mounting.
What do EA and EM mean on NTN spherical roller bearings?
EA is the NTN standard-capacity/high-capacity execution with a pressed sheet-steel window cage; EM is the high-capacity execution with a one-piece machined brass cage. Both use the optimised symmetric-roller design, but cage identity changes mass, speed behaviour and suitability for duties like vibrating screens, so they are separate order numbers. 24084B is the basic execution.
What do D1 and W33 mean on 24084B?
24084B is listed without a D1/W33 outer-ring groove in 2203E; lubrication is supplied from the ring sides. D1 (NTN spelling) and W33 add the annular groove plus holes and are ordered as distinct suffixed executions of the same envelope.
How much misalignment and axial load can 24084B take?
The sphered outer raceway compensates static and dynamic misalignment in the order of 1–2° (verify the exact 2203E figure for the 24000 series); beyond that, load concentrates on one roller row. Load is predominantly radial with a moderate axial share in either direction — 4300 kN C / 8450 kN C0 — but sustained pure axial load is not recommended because it unloads one row.
Reviewed & verified by the MPN Base engineering desk against source catalog NTN Ball and Roller Bearings CAT.No.2203E on 2026-10-01. Read our editorial & correction policy.